Unobservable Entites v. Observable Entities

Now we typically tend to think that certain things exist, like other people experiencing pain/pleasure, the existence of apples, flexible people, electrons, and the color red. We tend to think these things exist because they are told to us by people that we trust (or are told to trust) or because we have an experience of them through the senses.

Now we can define an observable entity as “that which can be experienced or observed directly”. An unobservable entity as a “postulated entity that cannot be experienced or observed directly”.

The natural question might be, what does ‘observed directly’ mean? Well, we would be working with our senses. That would be, sight, touch, sound, taste, & smell. Observed directly would be those things that are presented to our consciousness by that of the senses. It basically means, that which is experienced. There is no inference that is made. Some call this a ‘particular fact’. All of our experiences are particular, and thus based on particular facts.

For example, I experience a sound. What makes the sound? That is an inference (albeit one that we make so fast that we tend not to notice it.) John Stuart Mill gave us an example of this.

“For in almost every act of our perceiving faculties, observation and inference are intimately blended. What we are said to observe is usually a compound result, of which one-tenth may be observation, and the remaining nine-tenths inference…I affirm, for example, that I hear a man’s voice. This would pass, in common language, for a direct perception. All, however, which is really perception, is that I hear a sound. That the sound is a voice, and that voice the voice of a man, are not perceptions but inferences.”A System of Logic, Rationcinative and Inductive

Now in the book Logic and Philosophy, they are talking about inductive inferences that we make. Now John Stuart Mill brought this up, in his book, that we use inductive inferences that we are hearing the voice of man. We are not hearing the voice of a man, yet we are hearing a sound. We make an inductive inference that the sound was that of man, because we had past experience of hearing that sound and seeing a man talking while we heard that voice.

“But there are other useful ways to divide [inductive inferences]. In particular it is important to distinguish between reasoning from what is observed to what is as yet unobserved but can be observed, and reasoning from what is observed to what even in principle cannot be observed.” Logic and Philosophy 10th edition

Now a classic example of inductive inference from what is observed goes as follows. At instance 1 I came across a swan and it was white. At instance 2 I came across a swan and it was white. At instance 3 I came across a swan and it was white…Therefore all swans are white. This means that the next swan that I should observe, it should be white. This is an inference based on direct knowledge. Nevertheless, we make inductive inferences that are not based on what we shall have directly knowledge on, like what causes what we shall directly observe. We find that we observe something, and we think there was a cause of what we observed that we cannot observe.

In order to account for what we observe, we postulate unobservable entities (we can also call them theoretical entities) to account for the observable entities. These theoretical entities are something that we cannot, in principle, ever observe. We only observe the consequences, which is what we observed to begin with. Thus, we created these theoretical entities to account for what we observed. We shall never observe these entities, but they are invoked in order to account for what we did observe.

Now the book Logic and Philosophy gives us 4 examples of theoretical entities:

“(1) Physical particles, such as electrons, which many scientists claim cannot be directly observed even in principle, constitute a kind of theoretical entity, for we must infer their existence.

(2) Dispositional properties (discussed briefly in Chapter 13) constitute another kind of theoretical entity. An example is the property of being flammable. We can observe that something burns, but not that it is flammable. Similarly, we can observe that something bends, but not that it is flexible. Burning and bending are observable properties; flammability and flexibility are dispositional properties. Since dispositional properties are not directly observable, we must infer their existence. they constitute a kind of theoretical entity.

(3) Mental events or mental experiences constitute still another kind of theoretical entity. however, this kind of theoretical entity is different from all others in that every given entity of this kind can be experienced by someone or other (namely, the person who “has” the mental experience), although it cannot be observed by anyone else. For instance, my pain can be (and is) experienced by me, but not anyone else. And your pain can be (and is) experienced by you, but not by anyone else. From your point of view, my pain is theoretical, while from my point of view, your pain is theoretical. this is different from the case with respect to, say, electrons because (according to many scientist) no one can directly observe electrons. (It should be noted that, according to one philosophical theory called neutral identity theory, consciousness is a brain process, and therefore is observable.)

(4) Finally, many philosophers consider all physical objects, material objects, or material substance to be theoretical entities. They believe that it is what they call sense data that we experience directly, and not the physical objects that may be causally related to them. If we believe in the existence of physical objects in addition to the existence of sense data, and perhaps causally related to sense data, then this belief (if rationally founded) will be based on inductive inferences from what we experience, namely, sense data, to their cause, namely, physical objects”

Before I continue on, I should give you the definition of what they state are dispositional properties. Dispositional properties are “an unobservable power or potential of an item”.

Now the first three, I think, should be obvious what they mean. Now the question might arise about the fourth on physical objects/material objects. The philosopher H.H. Price gives a good example of how they would be theoretical entities.

“When I see a tomato there is much that I can doubt. I can doubt whether it is a tomato that I am seeing, and not a cleverly painted piece of wax. I can doubt whether there is any material thing there at all. Perhaps what I took for a tomato was really a reflection; perhaps I am even the victim of some hallucination. One thing however I cannot doubt: that there exists a red patch of a round and somewhat bulgy shape, standing out from a background of other colour-patches, and having a certain visual depth, and that this whole field of colour is directly present to my consciousness. What the red patch is, whether a substance, or a state of a substance, or an event, whether it is physical or psychical or neither, are questions that we may doubt about. But that something is red and round then and there I cannot doubt. Whether the something persists even for a moment before and after it is present to my consciousness, whether other minds can be conscious of it as well as I, may be doubted. And when I say that it is `directly’ present to my consciousness, I mean that my consciousness of it is not reached by inference, nor by any other intellectual process (such as abstraction or intuitive induction), nor by any passage from sign to significate. There obviously must be some sort or sorts of presence to consciousness which can be called `direct’ in this sense, else we should have an infinite regress. Analogously, when I am in the situations called `touching something’, `hearing it’, `smelling it’, etc., in each case there is something which at that moment indubitably exists-a pressure (or prement patch), a noise, a smell; and that something is directly present to my consciousness.”Perception

“Obviously, we must distinguish the given from the object which is given. The given is presentation of something real, in the normal case at least; what is given (given in part) is this real object involves its categori[c]al interpretation; the real object, as known, is a construction put upon this experience of it, and includes much which is not, at the moment, given in the presentation.”

John Stuart Mill says about the same thing:

“I affirm, again, that I saw my brother at a certain hour this morning. If any proposition concerning a matter of fact would commonly be said to be known by the direct testimony of the senses, this surely would be so. The truth, however, is far otherwise. I only saw a certain colored surface; or rather I had the kind of visual sensations which are usually produced by a colored surface; and from these as marks, known to be such by previous experience, I concluded that I saw my brother.”

George Berkeley gives us another example of what is going on here:

“By sight I have the ideas of light and colours, with their several degrees and variations. By touch I perceive hard and soft, heat and cold, motion and resistance, and of all these more and less either as to quantity or degree. Smelling furnishes me with odours; the palate with tastes; and hearing conveys sounds to the mind in all their variety of tone and composition. And as several of these are observed to accompany each other, they come to be marked by one name, and so to be reputed as one thing. Thus, for example a certain colour, taste, smell, figure and consistence having been observed to go together, are accounted one distinct thing, signified by the name apple. Other collections of ideas constitute a stone, a tree, a book, and the like sensible things–which as they are pleasing or disagreeable excite the passions of love, hatred, joy, grief, and so forth.”

Berkeley’s use of ‘ideas’ would be what C.I. Lewis, H.H. Price, and the authors of Logic and Philosophy, call sense data. Berkeley gives us a good example of this, when he talks about all the sense data that form what we call an apple. Now C.I. Lewis calls this a categorical interpretation. These names are just categories. We categorize all these sense data found to go together, and we give it a concept. We call this concept an apple. Thus, we do not observe an apple, but we observe a whole collection, a bundle, of sense data found together, which we give a name to. This name represents an unobservable entity. We do not directly observe an apple, but we directly observe sense data.

W.T. Stace in The Nature of the World: An Essay on Phenomenalistic Metaphysics, gives us another example of what is going.

“Consider the meaning of ‘horse’. A particular horse is a certain pattern of sense data (possibly with the addition of non-sensuous data). The meaning of the general term ‘horse’ is the concept of such patterns.”

Another way that might be helpful in understand this is a painting done by René François Ghislain Magritte. What it says, in French, is “This is not a pipe”

We apply a concept to this sense data of shape and color. We apply the concept “pipe” to bundle of sense data. It is not a pipe, but we take the concept to be the thing signified by the concept (the bundle of sense data).

Now electrons, soluble, your (not mine) pain, and an apple, are all theoretical entities. I have to construct these theoretical entities in order to form a picture of the world and predict what things I shall observe. The main point that can be taken away is this: We construct theoretical entities (unobservable entities) in order to predict what shall be directly presented to our senses (observable entities).

W. T. Stace gives us a good formulation of what is going in his book Theory of Existence and Meaning:

“All truth, all knowledge, we shall find, takes its origin from the given, is built thereon as a fabric of interwoven constructions, inferences, and abstractions. The constructional element in especial will be found to permeate all knowledge from the bottom to the top.”

What we do is make an observation. We find nothing that lead to what we observed. Thus, in order to account for this observation, we create a theoretical entity. We construct this theoretical entity that was never presented to our sense. Once we do this, we make an inference, based on the construction of this theoretical entity, to make an inference of what else we shall observe based on this theoretical entity.

Now to fit this in, even more, with Direct v. Indirect knowledge, we can use the conditional statement of P–>Q. Now, in order to have a better idea of this conditional statement, somethings should be made clear about the implications of it. In order to do this, I think a truth table shall do to help one understand it.

Now P and Q are statements of their own. They stand on their own. What we are doing is connecting these two statements together in a conditional statement. For example: P= the Eiffel Tower is in Paris; Q= Saturn is a planet. Now each of these statements, following the Law of Excluded Middle, is either true or false. That is why that we see T and F in the truth table under each symbol of P and Q.

What we are doing is connecting each of those individual statements together under a conditional statement. Now the conditional statement is hypothetical in nature. One is not asserting that the antecedent (P) or its consequent (Q) are true. All one is asserting that if the antecedent is true, then the consequent is true. Another example is this: If it is raining, then the ground is wet. This is completely hypothetical, and is not stating that either of its components are true. Thus, we can reformulate it in another: Assuming that it is raining, the ground is wet.

Now our unobservable entities, theoretical entities, are things that we construct, and state that they have a causal influence. We are assuming that they exist, and that their existence leads to observable effects that we do in fact observe. In fact, we already observed something and construct these entities and assume that they exist in order to account for our observations, and derive further observations.

However, we run into a logical problem. Notice line three of the truth table under P–>Q. We notice that P could be false, and Q could be true. Now if P is an unobservable entity and Q is an observable entity, then we will know that the observable entity is true. What we will not know is that the unobservable entity is true. In fact, ~P could be true and lead to the same observable entity. In fact, ~P contains a logical infinity of other unobservable entities that lead to the same observable entity.Thus, we are left with an infinity of unobservable entities that have the same causal effect as P.

So unobservable entities have practical value to us, which is predicting observable entities. Nevertheless, we have no reason to accept the existence of such unobservable entities because there are an infinity of unobservable entities that all have the same effects. The problem is that they would all have an infinity of different concepts and entities that underlie them. Thus, we cannot decide if they really do exist or not. However, we can say that they are useful instruments.

Another problem is this: Say we have an unobservable entity X. Now this unobservable entity is a complete model of itself, and makes a wide range of predictions of what we shall observe. This model also states what we shall not observe. The problem becomes is that there is an infinity of unobservable entities that are ~X and make all the same exact predictions of what we shall observe, and makes no more predictions than X. However, there is also an infinity of unobservable entities that make the same exact predictions as X, but makes even more predictions. However, this goes on with any unobservable entity.

What one can take away from this is something that seems to be counter-intuitive. Most of what we believe is theoretical constructions that have no knowable existence. In fact, we can use an analogy. Most of what we believe to exist is like all of the water in the world. What we do know to exist is but a drop of water.

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This entry was posted on April 14, 2011 at 12:01 AM and is filed under Philosophy.
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